1. Field of Invention
The present invention relates to an circuit with the AND, NAND, NOR and OR functions. More particularly, the present invention relates to an circuit with the AND, NAND, NOR and OR functions configured by several magnetic transistors.
2. Description of Related Art
‘AND’, ‘NAND’, ‘NOR’, and ‘OR’ logic circuits are very important for IC circuit design. The designer can combine these four logic circuits each other or with other logic circuits to implement the required functions.
FIG. 1 is a CMOS circuit with the NOR logic function of the prior art. The CMOS circuit has two PMOS transistors 100 and 130 coupled in series, and two NMOS transistors 160 and 190 coupled in parallel. The PMOS transistor 100 couples to the high voltage end 120, and the NMOS transistors 160 and 190 couple to the low voltage end 140. The input signal ‘X’ at the input end 110 controls the PMOS transistor 100 and NMOS transistor 160. The Input signal ‘Y’ at input end 150 controls the PMOS transistor 130 and NMOS transistor 190. The CMOS circuit generates the NOR logic function (output=(X+Y)′) at the output end 170.
The Giant Magnetoresistance Effect (GMR) is a quantum mechanical effect observed in structures with alternating thin magnetic and thin nonmagnetic sections. The GMR effect shows a significant change in electrical resistance from the zero-field high resistance state to the high-field low resistance state according to an applied external field.
Therefore, the GMR effect can be used to design the magnetic transistor. Thus, magnetic transistors can further be used to integrate a magnetic circuit without the expensive process and equipment. The magnetic circuit can be designed and manufactured with short programming time and high density.
Moreover, each ordinary logic circuit has only one function individually. Therefore, the ordinary circuits have to be designed or manufactured separately to implement a function. The magnetic transistor circuit presented here can generate the AND, NAND, NOR and OR functions by the same circuit. Therefore, the design and manufacture cost can be reduced more than before.
For the foregoing reasons, there is a need to have a magnetic transistor circuit integrated by magnetic transistors.